Numerical analysis of Dielectric Barrier Discharge Plasma Actuators for supersonic flow applications

Abstract

Surface Dielectric Barrier Discharge Plasma Actuator (SDBD PA) is a device that allows for a flow control near a surface of an object. In its simplest form the device consists of one electrode exposed to the atmosphere, dielectric and encapsulated grounded electrode. The device generates strong electric due to high voltage applied to the exposed electrode. Under the effect of the strong electric field the gas in the atmosphere is ionized and turns into plasma, which is manipulated by changing the electric field. The energy from the plasma is transferred to the surrounding gas through particle collisions allowing for the airflow control.The current work is concentrated on the supersonic applications of SDBD PA and aims at answering two questions:• What effects does supersonic shock have on plasma generated by SDBD PA?• What effects does SDBD PA have on supersonic shock?To answer these questions an OpenFOAM solver was developed that allows to simulate plasma within a supersonic flow. The solver is based on electron-positive nitrogen ions drift-diffusion model for plasma. Several simulations are performed to observe the plasma behaviour: plasma propagation through a frozen shock along a flat plate, supersonic flow under free-slip and no-slip conditions around a wedge with SDBD PA at the tip of the wedge. The Mach number varied from 1.3 to 2, depending on the simulation. φ E V Electric potential Superscript * Excited molecules Subscript c Charge e Electrons i Ions k Species k (e.g. ions, electrons) p Positive ions xxi